package com.wang.book.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.wang.book.entity.BookType;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
@Mapper
public interface BookTypeMapper extends BaseMapper<BookType> {
    @Select("SELECT COUNT(*) FROM book WHERE type_no = #{typeNo}")
    int countBooksByType(Integer typeNo);

}